I think a lot of transpeople are accepting and open minded, because they know themselves what it's like to be judged. But then again, there are close minded pricks everywhere, also in the trans world. (and I see transpeople can sometimes fight pretty hard on who is 'trans enough' and who is not, yadda yadda)
It could also be because I'm open minded myself, and I automatically get attracted to likeminded people. I have been on a dreadlocks forum which had a similar 'family' feeling where everybody supported each other, same on the forum of the LARP group I'm a member of. I think it's because all three of these groups (transpeople, dreadheads, larpers) are minorities who generally experience enough hate from the OUTSIDE world already, so have to cling together like family in order to stay together and withstand all that criticism.
I have ventured through many subcultures in my life, and I generally find them to be a lot more pleasant and accepting environment than the mainstream stuff. All of my larp friends were totally okay with me being trans right away, and respectfully called me my preferred name and pronouns, like WOW! And not ONE, but ALL OF THEM! (not saying larpers can't be pricks, but the ones I had as friends sure weren't!)
But for the rest... I don't think there's really a typical 'trans personality' or whatever, though some character traits (like introversion) might be more present than in the cisgender world because of our 'common heritage' and a childhood/teenage years that often were full of angst and confusion. You learn to deal with things differently by being rejected, which I think most of us have been multiple times.